Method and apparatus for making artificial silk



J. M. LEAVIER METHOD AND APPARATUS FOR MAKING ARTIFICIAL SILK Filed Sept. 1924 h all T j JAMES M. LEAWR, F GARLAND, CALIFORNIA, ASSIGNOR TO THE PACIFIC LUMBER CCAN'Y, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF MAINE.

METHOD AND APPARATUS FUR t In ING' ARTIFICIAL SILK.

This invention relates to the forming or s0-called spinning of threads from viscous solutions generally, and particularly to the spinning of such threads in the making of artificial silk.

The objects of my invention are to provide a method and apparatus for the above mentioned purpose which will be simpler and more ed'ective than any with which T am acquainted.

It might be mentioned that in the earlier methods of spinning artificial silk the filaments composing the threads were ejected from very minute orifices into various setting or precipitating baths, and gavemuch trouble through stoppage of the orifices due to their fineness; and that recently more attention has been directed to the use or larger orifices followed by stretching of the formed thread or filament after precipitation, and

- to a certain extent during the forming thereof, and to a slight extent just prior to the setting of the filaments.

But I have found that ii the nozzles are considerably larger than heretofore used and the viscous solution is fed therethrough under a constant pressure; maintained either by pumping or gravity; and per mitted to fall vertically from the nozzle through a considerable air. space (usually from one to several feet) that the method at once assumes a totally different com-- mercial aspect, for the thread filaments, or rather the viscous streams from which they are formed, in falling this relatively great distance take on the acceleration due to gravity which backed up by the feeding pressure of the material results in a very high speed of production, while at the same time the great distance of falling through the air reduces the filaments to any desired fineness of perfect rotundity.

This however is not the end of my process or method for great diificulty is found in properly setting such high speed minute streams into filaments in proper orderly arrangement or relation one to the other, and without breakage. The ordinary funnel and liquid methods are entirely too violent in their mechanical action, for, unless the setting liquid has a surface speed of travel substantially synchronous with that oil the falling filament streams, yet without violent agitation, good results cannot be secured, and also, after the initial setting it is desirable that the speed of flow of the solution and travel of the filaments should not be retarded, but should it possible always tend to increase somewhat until the filaments are twisted or otherwise compacted into a thread and wound upon a receiving reel for washing and drying.

My apparatus for carrying out the above described method of producing threads from viscous material is shown in the ac'c ompanying drawings and in which Figure I is an elevation of my apparatus on a reduced scale and with some of its parts shown in section, Figure 2 is a plan view, of the ejecting nozzle shown approximately full size, Figure 3 is a cross section or the nozzle taken along the line 33 of Figure 2 showing the interior form of the device with a small feeding well above each orifice, Figure 4 is an enlarged representation of a portion of my special variable pitch open helicoid filament compacting device, and Figure 5 is a front view of the precipitating chute which receives and guides the filaments to thread formation and with ever increasing speed delivers them into the helicoid device.

In further detail the apparatus comprises a suitable frame 1 supporting a receptacle 2 for the viscous solution, and a receptacle 3 for the setting solution.

The viscous solution is maintained at a contant level 4 within the receptacle or t ed thereto under constant pressure by any suitable means not shown, and the setting liquid 5 is maintained in its receptacle in a similar manner, so that a perfectly uniform flow of either solution may be obtained.

From the bottom of the setting solution receptacle extends a pipe 6 controlled by a valve 7 for discharging the solution into a well 8 supported just beneath the lower end 6' of the pipe, and from the well extends a downwardly inclined chute 9 connected to the well by a flat portion 10 for delivery of an even sheet of liquid to the chute from the surface 5 of the liquid in the well.

The chute has an increasing incline towards its lower end, terminating in a vertical drop, and a pair of sides 11 are proill till) vided which converge at the lower end of the chute as shown in Figure 5.

From the viscous solution receptacle extends a pipe 12 having a lower section 12 25 telescoping thereover and adjustable there- I along by means of a clamp screw 13.

The lower section 12' has a control valve 14 and carries at its extreme lower end a multiple nozzle 15 for ejectin a plurality of viscous streams directly ownward as shown, at 16 to be intercepted by the flowing sheet of setting solution from the well, and which sets or precipitates them to the form of filaments and diverts them at an angle all to one side of the path of falling of the streams.

. viscose from openings of about a millimeter or more depending somewhat on the force of the discharge of the material from the openings and the size of the filaments desired. With orifices an eighth of an inch in diameter and with a foot head of ten per cent solution above the nozzle, several feet of air space between the nozzle and setting bath produced very fine filaments at a very high speed of production.

Figure 2 shows in plan the full size arrangement of a nozzle successively employed, and discharging thirty streams through the orifices 17. The orifices are arranged in parallel rows and the nozzle is rotated with the telescopic pipe 12' to bring it to an angle with the travel of the setting solution in thechute so that the filaments will be carried to the left of the falling streams in side by side relation without interference, as shown in Figure 2 at 18 and as they are also designated in the chute 9 in their descent after first contact with the setting solution.

The nozzle may be constructed in the ordinary manner of small inserted tubes, but I show a simple way of forming it from a plate 19 grooved at 20 in opposite directions to form the discharging necks 21 through which the orifices 17 are drilled. Just above each orifice is a larger one 22 to serve as a feeding well for its particular orifice, and above the feeding Wells the metal may be tapered to the wells by grooving as described for the face of the nozzle, or by countersinking, either construction being indicated at 23. The plate may be soldered to the tubular reservoir portion 15 along the dotted line 24 or made integral.

The filaments 18 it will be observed are in the form of a fiat ribbon as they flow down the chute, and the converging sides of the chute gradually force the ribbon together to a thread like form, and with increasing speed of travel as they enter the helicoidal twister This device takes the form of a helicoidal chute, preferably of longer pitch at the upper end as indicated at 25' and progressively changing to a shorter pitch at the lower end as indicated at 25" so that the thread 18 enters gently and is spun around and compacted with increasing rapidity as it progresses, then gently ejected from the gra ual curve 26 at the lower end as a compacted thread 18".

A portion of my helicoidal device is shown enlarged in Figure 4 and it will be seen that it is preferably an open chute having an outer wall 25, and a lower wall or bottom 25, and a central core 25.

In passing. through this device with great speed the solution tends to hug the outer wall and the thread is compacted around the core, therefore it is desirable that the gradual change of pitch of the chute should be such as to compensate for the acceleration due to gravity to maintain a substantially uniform progress of the thread through the device, so that it will not be stretched against the core and slowed up thereby; but fair results may be secured even with a chute of constant pitch if properly proportioned.

It should be noted that the helicoid chute, as well as the upper chute 9, being entirely open on top for their full length, it is simplicity itself to start the filaments therethrough in beginning work, and that any in itial blocking up of the passages may be instantly removed as there is no complicated rifled or rotating closed tubular devices difficultof access in case of trouble, or in cleaning up, tho I wish to say that whatever novelty my helicoidal device possesses even if made with closed sides I wish to cover in my claims hereto appended.

From the helicoidal chute the compacted thread 18" descends with the setting solution to a tank 27 where the solution is maintained at a fixed level 5 by any suitable means not shown, and the thread is passed over a wheel 28 revolvable in the solution as indicated.

From the wheel 28 the thread passes through the solution to another wheel or reel 29 also revolving in the solution in the same direction but at a greater surface speed so as to stretch the thread at the point A be tween the wheels.

In commercial production the wheel or reel 29 upon which the thread is wound. may advantageously be given a reciprocatory motion in an axial direction by any of the well known means of so doing, so as to wind the thread in crossed layers upon its surface.

The wheel 28 may be a retarded idler, or a positively driven one as shown from the lit hit

neeucao wheel 29 through means of the chain indicated at 30, and the power to drive the wind r ing whe 29 delivered from any source of power through the chain indicated at 31 passing over a sprocket 31 secured either to the wheel or to its axle. 1

It is desirable that the final thread B be wound upon a detachable ring or band 32 slipped over the rim of the Wheel 29 so that when suflicient thread is wound upon it the rim may be quickly slipped ofi' for replacement with another, and to facilitate this procedure both wheels are revolvably sup ported on axles projecting from one side only with the other sides of the wheels free, thus making it a very simple matter to change rims or start the thread over the wheels in the beginning, or after placing a fresh rim in place.

Upon considering the apparatus as de scribed it will be seen that no obstruction passes the path of the thread at any point of its making, so that it is freely accessible at any'point from the discharge nozzle to the finished thread upon the reel 29, thus gifeatly facilitating starting the filaments t rough the apparatus, observing their proper operation at all points of the process, removing stoppage material in getting the apparatus properly adjusted, and in taking care of the finished product.

ll claim l. The method of forming thread filaments from viscous solutions, which consists in discharging the material downward in a plurality of streams, permitting the streams to fall through the air to reduce them in diameter to a fraction of their starting diameter, and receiving the falling till hit

streams on a moving sheet of setting solut1on havmg a surface speed substantially synchronous with that of the falling streams at their point of contact therewith.

2. The method of forming thread filaments from viscous solutions, which consists in discharging the material downward in a plurality of streams, permitting the streams to fall through the air to reduce them to a fraction of their starting diameter, and receiving them on a fiat moving sheet of setting solution having a surfa e speed of travel substantially synchronous with the speed of the falling streams at their point of contact therewith.

3. The method of forming thread filaments from viscous solutions, which consists in discharging the material downward in a plurality of streams, permitting the streams to fall throu h the air to reduce them to a fraction of their starting diameter, and of receiving them on a moving sheet of setting solution having'a speed substantially equal to that of the falling streams at theirpoint of contact therewith and of progressively increasing speed thereafter.

4:. The method of forming thread fila ments from viscous solutions, which consists in discharging the material downward in a plurality of streams, permitting the streams to fall through the air to reduce them in diameter to a fraction of their starting size, and of receiving them on a moving sheet of setting solution traveling at a descending incline to carry the filaments all in a common angular direction from their points of contact with the solution in falling.

5. The method of forming thread filaments from viscous solutions, which consists in discharging the material downward in a plurality of streams, permitting the streams to fall through a space to reduce them to a fraction of their starting diameter, and of receiving them on a moving sheet of setting solution traveling across their path of falling, said streams being arranged to fall in a manner to be carried away with said moving sheet of setting solution substantially in the form of a fiat ribbon.

6. The method of forming thread filaments from viscous solutions, which consists in discharging the material downward in a plurality of streams, permitting the streams to fall through a space to reduce them to a fraction of their starting diameter, and of receiving them on a moving sheet of setting solution traveling across their path of falling, said streams being arranged to fall in a manner to be carried away with said moving sheet of setting solution in the form of a flat ribbon with the filaments in side by side relation.

7. The method of forming thread filaments from viscous solutions, which consists in discharging the material downward in a plurality of streams,-permitting the streams to fall through a space to reduce them to a fraction of their starting diameter, and of receiving them on a moving sheet'of setting solution traveling at' a descending incline across their paths of falling whereby they are carried away in the form of a flat ribbon, and of then concentrating the filaments into a thread,

8. The method of forming thread .filaments from viscous solutions, which com prises discharging thematerial downward in a plurality of streams, permitting the streams to fall through a s ace sufficient to reduce them to a fraction 0 their starting diameter, receiving them on a moving sheet ice of setting solution traveling across their path of falling, converging the filaments thus formed to a thread-like form and of then passing them downwardly through a helicoidal path. 1

9. The method, of forming thread filaments from viscous solutions, which comprises discharging the material downward in a plurality of streams, permittin the streams to fall through a space su cient bath of settin to reduce them to a fraction of their starting diameter, receiving them in a moving solution traveling across their path of alling, converging the filaments thus formed to a thread-like form and passing them together with the bath downwardly through a helicoidal path of progressively decreasing pitch.

10. The method of forming thread filaments from viscous solutions, which comprises dischargin the material downward in a plurality streams,.permitting the streams to fall through a space to reduce them to a fraction of their starting diameter, receiving them in a .bath of setting solution moving across their path of falling, converging the filaments thus formed to a thread-like form and passing the converged filaments and bath downwardly through a helicoidal path at a substantially uniform speed of travel while passing therethrough.

11. The method of forming thread filaments from a viscous solution, which comprises discharging the solution downward, in

'a plurality of streams, permitting the streams to fall through space to reduce them to a fraction of their starting diameter, receiving them in a bath of settin solution v moving across their path of falling, converging the filaments thus formed into a thread-like form and passing them together with the bath downwardly through a helicoidal path of progressively decreasing pitch while maintaining the c s eed of travel through said path substantially constant.

12. The method of forming thread filaments from a viscous solution, which comprises discharging the material downward in a plurality of streams, permitting the streams to fall through a space to reduce them to a fraction of their starting diameter, receiving them in a traveling bath of setting solution passing across their path of falling, converging the filaments thus formed into a thread-like form and then passing them together with the setting solution through a helicoidal path and into a further bath of the setting solution and of therein mechanically stretching the thread.

13. The method of forming thread from a viscous solution, which consists in discharging the material downward in a plurality of streams, permitting the streams to fall through a space to reduce them to a fraction of thelr starting diameter, receiving them on a moving sheet of settin solution traveling across their paths of fa ling whereby they are carried to one side of their place of falling, compacting the filaments thus formed into a thread, and of stretching the thread after compacting all while t-raveling and immersed in the setting solution.

14. In a method of forming thread as specified in claim 13, the compacting of the filaments being carried out substantially without tensioning the same.

15. The method of stretch spinnin of thread filaments from viscose solution, w iich comprises discharging a stream of cellulose sodium xanthate solution downward through an air space before setting, and intercepting the stream in a setting solution at a vertical distance under the point of discharge sufficient to reduce the unset stream of viscose to a fraction of? its starting diameter so as to form a precipitated filament of reduced diameter.

16. The method of stretch spinning of thread filaments from viscose solution, which comprises discharging a stream of cellulose sodium xanthate solution downward through an air space before setting, and intercepting the unset stream in a setting solution at a vertical distance under the point of discharge of the stream not less than one hundred times the diameter of the stream at its point of discharge.

17. For the forming of thread filaments from a viscose solution, an inclined chute, means for maintaining a stream of viscose setting bath running down said chute, a multiple stream viscose ejector spacedly arranged above said chute and bath directed to discharge streams of viscose downwardly through an air space to the bath in the inclinedv portion of the chute for travel with said bath.

18. In apparatus as specified in claim 17, said chute having converging sides adapted to force the filaments together into a threadlike form as they pass along the chute.

19. For the formation of thread filaments from viscous solutions, means for discharging streams of the solution into a setting solution, means for guiding the filaments while in the solution into thread relation, and a downwardly directed helicoidal chute arranged to receive the filaments so related together with the setting solution and adapted to compact the filaments into a thread in descent therethrough.

20. In a structure as specified in claim 19, said chute being open substantially for its length whereby the thread is accessible therealong.

21. In a structure as specified in claim 19, said chute being of decreasing pitch in its downward descent.

22. For the formation of thread filaments from a viscous solution discharged from an ejector and set in a precipitating solution,

a device into which the filaments are guided comprising a helicoidal channel directed downwar ly and arranged to receive the filaments and setting solution at its upper end.

23. In a structure as specified in claim 22, said helicoidal channel having a progressively varying pitch.

24. In, a structure as specified in claim neonate 22, said helicoidal channel having a central rod around which the filaments travel in their descent.

v 25. In a structure as specified in claim 22, said helicoidal channel being open on top from end to end.

26'. Apparatus for forming a band 01E artificial silk filaments comprising a spinning nozzle provided with a plurality of rows of ejection orifices directed downwardly, means for removing a' bundle of falling filament streams from said nozzle in a lateral direction from the path of falling, and means for varying the angle of the lateral removal of the streams with res ect to the rows of orifices, whereby to pro uce a band of evenly spaced filaments spaced a distance apart depending on the relative angle or removal with respect to the rows oil orifices.

27. For the forming of thread filaments iErom viscose solution, an inclined open chute, means for malntainlng a vlscose setting bath running down sald chute, a

multiple stream viscose ejector spacedly to form a thread, means supporting the thread in the solution after compacting, and further means for stretching the thread after leaving said supporting means and while still immersed in the solution.

30. ln a structure as specified in claim 29, said further means comprising a device immersed in the solution over which the thread is guided, and a reel immersed in the solution receiving the thread and rotated at a speed to cause stretching out the thread between the device and the reel.

31. In a structure as specified in claim 29, said further means comprising a roller immersed in the setting solution and over which the thread passes, and a receiving reel for the thread, the roll and reel having different surface speeds for stretching the thread extending between them.

32. For the formation of a thread from a viscous solution, a multiple stream ejector for discharging the solution in a plurality of streams, means including a moving setting solution adapted to receive and set the streams to fine filaments and for carrying same away from the point of contact or the streams therewith, means for compacting the filaments while being carried in the solution, and means for receiving the thread thus formed, all of said means presenting a freely open side substantially the length of travel of the filaments and thread,

JAMES M. LEAVER.

(Nil 

